Grinding wheel truing apparatus



Aug. 13, 1946.

B. s. T. BISHOP ET AL 2,405,551 GRINDING WHEEL TRUING APPARATUS I Filed June 8, 1944 2 Sheets-Sheet ,L

'Jrew A g- B.- s. T. BISHOP ET AL GRINDING WHEEL TRUING APPARATUS Filed June 8, 1944 2 Sheets-Sheet -2 Patented Aug. 13, 1946 2,405,551 GRINDING WHEEL TRUDV G APPARATUS Shrewsbury, and Frank A. Bicknell, Worcester, Mass, assignors to Leland- Gifford Company, Worcester, Mass, a corporation of Massachusetts Benjamin S. '1. Bishop,

' normal operations Application June 8, 1944, Serial No. 539,358 6 Claims. (01. 12511) This invention relates to improvements in grinding wheel truing apparatus. More particularly it relates to apparatus which may be in the form of an attachment for grinding machines and which can have its diamonds or other truing elements preliminarily accurately set in readiness for a wheel truing operation at the will of the machine operator.

It is an object of our invention to provide a wheel truing apparatus having separately mounted truing diamonds, each separately movable into truing relation with a different face of the cutting edge of the grinding Wheel, and each preliminarily set in its mounting means for correct precision traverse of a face of the cutting edge of the Wheel when moved by the operator to efiect a truing of that face. We provide swinging diamond-carrying arms, each swingable on an axis angularly related to the wheel face which is to be traversed by its diamond. Preferably the arms are mounted on an adjustable member which can be secured on a suitable fixed part of a grinding machine where the attachment, during periods of non-use, will not interfere with the regular and However, the diamond-carrying arms are constantly in readiness to be moved to bring each diamond in succession into truing relation to the grinding wheel when the wheel is in a predetermined position with respect to the work driving spindle.

Another object of our present invention is to provide means on the truing apparatus for micrometer adjustment of the arm-carrying member in directions toward and from the wheel for 35 predetermining the amount to be removed from each wheel face while preserving the preliminarily set angular relation between an arm, its diamond and the particular wheel face which is to be dressed.

Still another object is to provide a diamond setting fixture for preliminary precise setting of each diamond in its swinging arm. A base is provided comparable to the base upon which the truing apparatus is to be mounted on the grinding machine, so that the ap aratus may be mounted on this fixture precisely as it will be mounted on the machine. A gage block is mounted on the fixture base and has a forward part formed with faces angularly related as are the faces of th cutting edge of the grinding wheel which is to be trued. Hence the diamond in each swinging arm may be set with relation to the proper gage face of the fixture and will be accurately set with relation to a wheel face when the apparatus subsequently is of the grinding machine.

mounted on a grinding machine. the setting of the diamonds without of micrometric adjustment of the member on which the diamond-carrying arm is mounted, a plate of predetermined thickness is used, it being laid first against one gage surface and then against the other gage surface and the diamonds being adjusted to bear against the plate surface which, in one position, faces one diamond and, in another position, faces another diamond.

It is, moreover, our object to generally improve the structure and operation of apparatus for truing grinding wheels.

In the accompanying drawings:

Figure l is a plan view of wheel truing appara tus embodying features of our invention, shown mounted on a grinding machine forward of and below the horizontal plane of the grinding wheel axis;

Figure 2 is an end elevation of the same with a portion in section on line 22 of Figure 1;

Figure 3 is a view similar to Figure 1 but with the diamond-carrying arms swung into truing relation to the grinding wheel;

Figure 4 is a plan view of the truing apparatus mounted on the diamond setting fixture; and

Figure 5 is an end elevation of Figure 4 showing one diamond carrying arm in position for setting its diamond with relation to the plate on the gage face. I

Referring to the drawings, an improved wheel truing device is shown as an attachment which can be mounted on a grinding machine in readimess to perform a wheel truing operation at the will of the operator. In the embodiment herein To facilitate the necessity it which are threaded into nuts I6, engaged in a T-slot 48 in the part I2 of the machine. Each nut i6 has a shank I! which extends out of the T-slot and seat in a recess 20 in the under side of base it] for ensuring a precision alignment of the base it relative to the T-slot H3. The base, between the bolts l4, I4 is formed at its under side with a wide groove 22 for receiving a slide member 24 which extends beyond the base both forwardly as at 25 and rear-wardly as at 28. At the forward projecting end of the slide there is mounted a block 35! on whose front face is the setting gage 32. The forward shank end of a screw :38 extends loosely through the gage and block with a graduated knob 35 on its extreme forward end for micrometer adjustment of the slide '24 by bringing particular graduations on the knob into register with a guide edge 38 formed at the cut-out 40 of a plate 42 secured on the top face of block 39. lhe inner end of screw 34 is threaded into the forward part of base l6 which serves as a fixed nut coacting with the screw for moving the slide relative to the base when the screw is rotated. A vertical threaded stud d6 rises from the slide and extends through aslot 48 in base 9 with a nut 50 on its upper end engaging the large diameter washer 52 for clamping the base and slide together in relatively adjusted positions. When nut 50 is loosened the stud can move in slot 48 to permit adjustments of the slide. A set screw 54 is provided in block 39 for locking screw 34 against accidental rotation after a micrometer setting of the slide.

The rearwardly projecting part 28 of the slide ha mounted thereon the two swinging arms 55, 53, each carrying a diamond 68.

At times of non-use, the arms '6, 58 lie flat as in Fig. l, in crossed relation with arm 58 overlying arm 56 and havin a shape for bridging arm 56 while its free end rests fiat on the surface ll of base it. Assuming a proper preliminary setting of the diamonds 68, and a proper adjusted relation between the slide member 24 and wheel i i, the wheel may be trued by merely causing the diamond-carrying arms 55 and 58 to traverse the faces of the grinding wheel which is being trued.

The preliminary setting of the diamonds in the arms 55, 53 may be accomplished prior to mounting the truing apparatus on the grinding machine. A special fixture is provided comprising a base i l having a top surface comparable with the machine surface on which the apparatus ultimately is to be mounted. The base 1i] has a T-slot '12 out of which the special nuts Hi can project and seat in the recesses 26 in the under side of the base if! of the truing apparatus, precisely as has been described in connection with the mounting of the apparatus on a machine. The bolts M engage the nuts iii to clamp base Hi on base IE with the slide member 24 projecting fore and aft of base it as previously described.

Base 56, however, projects rearwardly beyond the slide and has mounted on its rear portion the upstanding member it on whose top is secured a gage plate 76 having its forward part shaped to provide the angularly related faces i8, 8% corresponding in position and angle to the faces (it of the grinding wheel 44. Hence, by setting the diamonds fit in arms 56, 58 for proper traverse respectively of faces 18 and 88, the diamonds will be properly set for truing wheel 4-3 when the apparatus is mounted on a grinding machine. Preferably, instead of setting the diamonds for traversing the faces 58, 833 of plate 53, a loose bar or plate 82 is provided which can be laid against the faces E8, 80 in succession thereby to project the angle of face so that the diamonds may be set relative to the outer surface of bar 82 without adjusting slide 24.

Ihe herein disclosed simple yet accurately effective means for truing a grinding wheel enables the truing elements, correctly and accurately set, to be ever ready in a non-interiering position, for use when needed We claim as our invention:

1. Grinding wheel truing apparatus comprising a fixed gage having a tapered part with faces angularly related precisely corresponding to the angular relation of the bevelled edge faces of a wheel which is to be trued, a horizontal support below and forward of said gage, a pair of arms pivotally mounted on said support and independently swingable on angularly related axes, a wheel truing element adjustably mounted on each said arm, said arms being adapted to rest on said support in generally horizontal positions below and forward of the gage, and means for swinging one said arm to bring its said truing element to position for adjusting its setting relative to a said gage surface while the other arm continues in its said generally horizontal position.

2. Grinding wheel truing apparatus comprising a fixed gage having a tapered part with faces angularly related precisely corresponding to the angular relation of the bevelled edge faces of a Wheel which is to be trued, a horizontal support below and forward of said gage, a pair of arms pivotally mounted on said support and independently swingable on angularly related axes, a wheel truing element adjustably mounted on each said arm, said arms being adapted to rest on said support in generally horizontal positions below and forward of the gage, means for swinging one said arm toward said gage to bring its said truing element into a position for adjustment of its setting relative to said gage while the other arm continues in its said generally horizontal position, and graduated means for adjusting said support toward and from said gage to set the truing element relative to said gage and, subsequently, to set the set truing element in any of various selected positions backward from the position of its setting relative to said gage, thereby to set the truing element for precision truing of a grinding wheel operating on work of any particular diameter.

3. In a grinding machine having a grinding wheel and having a fixed horizontal surface below and forward of the wheel above which surface is the work position of the machine, wheel truing apparatus comprising a horizontal base adapted to be mounted on said fixed horizontal surface below and forward of the grinding wheel, a pair of arms pivotally mounted on said base and independently swingable on angularly related axes, a wheel truing element mounted on each arm, said arms being adapted to rest idly on said base in generally horizontal positions when a grinding operation is being performed by said wheel on work in said work position, and means for swinging one said arm independently of the other arm to bring its said truing, element into truing engagement with the grinding wheel when said work position is vacant.

4. In a grinding machine having a grinding wheel and having a horizontal surface below and forward of the wheel above which surface is the work position of the machine, wheel truing apparatus comprising a horizontal base adapted to be mounted on said horizontal surface below and forward of the grinding wheel, a pair of arms pivotally mounted on said base and independently swingabl on angularly related axes, a wheel truing element mounted on each arm, said arms being adapted to rest idly on said base forwardly of the grinding wheel and below the said work position when a grinding operation is being performed by said wheel on work in said work position, with one said arm crossing over the other, means for swinging said crossing over arm to bring its truing element into truing engagement with the grinding wheel when said work position is vacant, and means for subsequently swinging said other arm to bring its truing element into truing engagement with the grinding wheel.

5. In a grinding machine having a grinding wheel mounted for rotation about a horizontal axis, wheel truing apparatus comprising a plurality of arms each pivotally mounted for swinging about an axis disposed in a horizontal plane substantially below the horizontal plane of the axis of said grinding wheel, said arms being adapted to rest in idling positions in which both arms extend approximately in the horizontal plane of their axes, with one arm extending across the other, and a truing element on each said arm, each said arm being swingable about its pivot from its said idling position to bring its said truing element into truing engagement with the grinding wheel.

6. In a grinding machine having a grinding wheel rotatably supported for rotation about a horizontal axis, wheel truing apparatus comprising an arm pivotally mounted on a horizontal pivot for swinging movement between an idle position in which the arm rests approximately in the horizontal plane of its axis of swinging forwardly of and below said grinding wheel, and wheel truing positions in which the arm is ad- -jacent peripheral regions of the wheel, a wheel truing element mounted on said arm outward from its axis of swinging, means on said arm for swinging it thereby to cause said Wheel truing element to traverse a said peripheral region of the wheel, and graduated means for moving the said arm bodily toward and from the grinding wheel a predetermined amount thereby to set the truing element selectively for truing the wheel working on any of various diameters of work.

BENJAMIN S. T. BISHOP. FRANK A. BICKNELL. 

